A4 vs A5 Paper Size: Exact Dimensions & Best Uses Compared
A4 paper measures 210 × 297 mm; A5 is exactly half at 148 × 210 mm. These are ISO 216 standards, so an A4 sheet cut parallel to its shorter edge yields two A5 pieces—no guesswork, no variation.
People confuse them because printers and notepads often show “A4/A5” in the same menu, and folding an A4 in half feels like “shrinking,” not switching formats. The mix-up costs money when bulk orders go to the wrong size.
Key Differences
A4 gives you twice the area—ideal for reports and flyers—while A5 slips into handbags and aircraft trays. A4 needs larger binders; A5 fits pocket folders. Ink cost per page halves on A5, but text shrinks 30 %.
Which One Should You Choose?
Pick A4 for contracts, school essays, or anything that must stay unfolded. Choose A5 for pocket diaries, quick sketches, or café menus that guests can lift with one hand. If portability beats space, A5 wins.
Examples and Daily Life
Your office printer defaults to A4 for invoices. Airlines hand out A5 immigration cards. Bullet-journal fans love dotted A5 notebooks because they fit coat pockets. Concert tickets? Usually A5 stubs—easy tear, easy keep.
Can A5 be scaled back to A4 without quality loss?
Yes, but you’ll need to enlarge 141 %; any raster image may pixelate, so use vector graphics or 300 dpi originals.
Is A4 legal for US government forms?
No, US forms default to Letter (216 × 279 mm). A4 is acceptable if specified, but margins must be reset to prevent clipping.
Why do Moleskine notebooks label “A5” yet feel smaller?
Moleskine uses “A5” loosely; their 145 × 210 mm cut saves leather, so it’s 3 mm narrower than true A5—close, but not exact.